96 
leaves  being  obovate  and  narrowed  into  the  petiole.  No  more 
description  of  it  has  been  published  (Hooker,  hi.  Journ.  Linn  Soc. 
XIX,  293).  In  Dr.  Haviland’S  Collections  of  Sarawak  PlantSu 
there  are  specimens  (No.  2170)  of  a Dyera  which  are  probably  of 
this  species,  of  which  the  leaves  are  of  the  shape  described,  but 
are  still  more  distinct  in  having  twice  as  many  nerves.  He  labels  it 
Jelutong,  and  found  it  flowering  in  December.  It  is  from  Dyera 
that  the  Jelutong  rubber  is  obtained.  Dyera  Costulataxs 
found  in  the  whole  of  the  Malay  Peninsula  growing  in  the  low 
lying  forests,  from  Singapore  to  Penang,  where  two  verv  large 
trees  were  formerly  used  as  land  marks  by  vessels  at  sea.  It 
occurs  also  in  Sumatra. 
Uses. — The  Jelutong  tree  produces  both  timber  and  a kind  of 
caoutchouc.  The  timber  is  soft  and  white,  and  was  formerly  used 
tor  models  and  Chinese  clogs  only,  being  easy  to  cut  but  it  is  not 
at  all  durable.  Of  late  years  it  has  been  used  for  planking  and 
boxes^  for  want  of  any  cheap  wood  as  suitable  (see  Bulletin.) 
Its  most  important  product  however,  is  its  latex,  formerly  chiefly  1 
used  to  adulterate  the  white  gutta  perchas  (Getah  Sundek)  from  j 
Payena  Leer'd.  But  for  some  years  the  Jelutong  Gutta  has  been  j 
imported  from  Borneo  chiefly  into  Singapore  and  exported  mainly 
to  America.  For  some  inexplicable  reason,  the  trade  name  was  j 
altered  a few  ymars  ago,  and  the  stuff  was  called  “ Pontianak  ” ; 
in  England,  which  naturally  caused  some  confusion  between  Gutta 
Pontianak  i.e.  Jelutong,  and  Pontianak  (nitta  percha,  i.e.,  Gutta  ^ 
percha  from  Poiuianak. 
The  latex  of  Jelutong  is  very  abundant  and  liquid,  pouring  out 
at  a cut.  It  IS  neither  acid  nor  alkaline,  being  quite  neutral,  speedi- 
ly coagulating  o)i  (exposure  to  air,  it  has  not  the  least  elasticity;, 
but  becomes  a hard  brittle  white  mass,  which  on  being  plunged  in 
hot  water  it  becomes  quite  plastic  like  putty  and  can  b(‘  moulded 
into  any  shape.  Owing  to  this  proi3erty,  it  was  at  one  time  used 
for  forming  mouldings  for  picture  frames  and  such  like  work  in 
place  of  plaster  of  Paris.  It  is  also  used  for  mixing  with  viscose 
fan  alkaline  cellulose  treated  with  carbon  bisulphide)  in  the  manufac- 
ture of  compound  rubber,  and  is  said  to  be  superior  to  Euphorbia 
aum  and  potato  rubber  as  a cheap  binding  ingredient  in  certain 
rubber  mixings  [India  Rubber  World).  Its  chief  use  appears  to 
be,  however,  for  making  a waterproofing  mixture  used  in  the  walls, 
floors  and  roofs  of  houses,  and  this  use  which  is  of  comparatively 
recent  date,  appears  to  be  the  cause  of  the  very  large  demand  for 
it  of  recent  years.  It  is  used  also  in  making  all  sorts  of  cheap 
rubber  goods  especially  rubber  shoes,  when  mixed  with  other 
materials. 
The  method  of  obtaining  the  Jelutong  is  described  by  Mr. 
Shf.i.FORI)  of  the  Sarawak  Museum,  as  follows: — 'Fhe  bark  of  the 
tree  is  nicked  in  several  places  and  the  gutta  exudes  from  the 
scars.  It  is  scraped  off  and  put  into  a receptacle,  if  not  thick 
enough  a white  powder  (probably  sago  flour)  is  added  to  it  to 
thi('ken  it:  Mr.  VoGLF.R,  of  Huttenbach  Brothers,  who  has  given 
me  much  information  on  tliis  subject  states  that  it  comes  into  the 
